_Schal%25C3%25A9n.png) Shape model of Schalén from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | Y. Väisälä |
| Discovery site | Turku Obs. |
| Discovery date | 26 August 1941 |
| Designations | |
| (1542) Schalén | |
Named after | Karl Schalén(astronomer)[2] |
| 1941 QE · 1927 BH 1936 UL · 1940 LP 1976 CA · A898 VD A924 NA | |
| main-belt · background[3] | |
| Orbital characteristics[1] | |
| Epoch 16 February 2017 (JD 2457800.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 117.73 yr (43,001 days) |
| Aphelion | 3.4510AU |
| Perihelion | 2.7343 AU |
| 3.0926 AU | |
| Eccentricity | 0.1159 |
| 5.44yr (1,987 days) | |
| 284.94° | |
| 0° 10m 52.32s / day | |
| Inclination | 2.7662° |
| 211.66° | |
| Physical characteristics | |
| Dimensions | 42.374±0.273 km[4] 45.05 km(derived)[3] 48.998±0.480 km[5] |
| 7.516±0.002h[6] | |
| 0.0501(derived)[3] 0.0509±0.0105[5] 0.068±0.003[4] | |
| SMASS =D[1][3] | |
| 10.4[5] · 10.6[1][3] | |
1542 Schalén (provisional designation1941 QE) is a backgroundasteroid from the outer region of theasteroid belt, approximately 45 kilometers in diameter. It was discovered on 26 August 1941, by Finnish astronomerYrjö Väisälä atTurku Observatory in Southwest Finland.[7] The darkD-type asteroid was later named after Swedish astronomerKarl Schalén.[2]
Schalén is abackground asteroid, located near the region of theThemis family, a dynamical family of outer-belt asteroids with nearly coplanar ecliptical orbits.[3] It orbits the Sun at a distance of 2.7–3.5 AU once every 5 years and 5 months (1,987 days). Its orbit has aneccentricity of 0.12 and aninclination of 3° with respect to theecliptic.[1] It was first identified asA898 VD atHeidelberg Observatory in 1898, extending the body'sobservation arc by 43 years prior to its official discovery observation at Turku.[7]
Schalén has a darkD-type spectrum, mostly found amongHildian asteroids andJupiter trojans.[8] Bodies with a D-type spectra are thought to have originated in theKuiper belt.
According to the 2014-result of the survey carried by NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission, Schalén measures 42.374 kilometers in diameter and its surface has analbedo of 0.068,[4] while theCollaborative Asteroid Lightcurve Link derives an albedo of 0.0509 and a diameter of 45.05 kilometers with anabsolute magnitude of 10.6.[3]
In November 2012, a rotationallightcurve of Schalén was obtained from photometric observations by astronomers at thePurple Mountain Observatory in collaboration with observatories in the United States. Lightcurve analysis gave a well-definedrotation period of 7.516 hours with a brightness variation of 0.49magnitude (U=3).[6]
Thisminor planet was named in honour of Swedish astronomer Karl Adam Wilhelm Schalén (1902–1993), who was a director of the SwedishLund Observatory.[2] The officialnaming citation was published by theMinor Planet Center on 20 February 1976 (M.P.C. 3930).[9]
